A leading humanitarian group is warning of potential chaos in Liberia, should president Charles Taylor step down before international peacekeepers move in. The International Rescue Committee is concerned Mr. Taylor's army might run amok.

The International Rescue Committee says the timing of international military involvement in Liberia is key to the immediate future of the country. The private humanitarian group, which has had relief workers in Liberia since 1996, is expressing concern about violence arising from a potential power vacuum there.

President Bush has not made a decision whether to send U.S. military forces into the West African nation, which was by freed American slaves.

The International Rescue Committee's West Africa regional director, Robert Warwick, is calling on President Bush to commit troops to Liberia before Mr. Taylor steps down.

"Our concern is that should Taylor leave prior to U.S. involvement, that that gap in timing, we don't know how long it would be, could create chaos and worsen the situation in Monrovia," he said.

Mr. Warwick expresses concern the troubled capital, a city of one million residents, is likely to bear the brunt of a deepening humanitarian crisis and increased fighting if a power vacuum occurs.

Mr. Warwick recently returned from the conflict-ridden city, where he spent several weeks and had to be evacuated during the height of fighting there.

Clashing rebel factions and a rising number of internally displaced refugees have complicated Liberia's situation. Recent looting crippled a number of non-governmental aid organizations in Monrovia, where large numbers of Liberians typically seek safety in times of crisis. Money, vehicles and equipment were stolen, severely damaging the aid agencies' capacity to provide relief.

Mr. Warwick says if Mr. Taylor leaves power, his army is likely to run wild through the capital, unless there is a foreign military presence to stop it.

"Certainly Taylor's forces, we anticipate would go on the rampage, looting, raping, getting access to as many supplies as they can and then perhaps repositioning themselves someplace in Monrovia or perhaps outside of Monrovia," he said.

The IRC official praised Jeremy Greenstock, Britain's U.N. ambassador who recently led a U.N. mission to Africa, for urging U.S. involvement in Liberia. He pointed to the British involvement in Sierra Leone as a model of success. The British approach included a combination of peacekeeping and offensive forces, deployed in regions where U.N. peacekeeping troops were also located.

Mr. Warwick is urging U.S. officials to provide a comprehensive approach to the crisis.

"Any involvement of the U.S. government really needs to be part of a regional approach and it needs to communicate and coordinate with the other international players in the region," he said. "If we don't do that, then what has happened in the past is these militia groups will just shift their location either into Guinea, or Sierra Leone or to the border area of Cote d'Ivoire and continue to destabilize the region."

The International Rescue Committee says close to a quarter million refugees are presently staying in Monrovia. Of 70 to 80 refugee camps in the capital, only three of those sites have health clinics, and six have some food distribution. Mr. Warwick called the number of refugees "mind-boggling," and says his organization is only scratching the surface.